Marking technique summary:
With patient in a standing position, first mark a horizontal line through the umbilicus and extend it on each side to the anticipated lateral limit of dissection. Next, make a vertical line through the umbilicus that extends from the sternum to the pubis. To complete the grid, in 5-cm intervals, mark the remaining horizontal and vertical lines and identify matching vertical lines with letter pairs (A, B, etc.).
Data from Pechter, E. The grid/staple adjunct to abdominoplasty. Plast Recontr Surg. 2006;118:1624-1630.
Dr. Pechter's grid notes
Since the horizontal lines and vertical lines are all 5 cm apart from one another, each box should be a square. Also, I mark every other line red (for clarity). Additionally, I don't usually make the grid continuously from top to bottom. I first make the horizontal line through the belly button and one or more lines above and below that at 5-cm intervals. But I mark the lowest line 5 cm above the commissure of the labia majora and then mark one or two lines at 5-cm intervals above that. This usually results in the removal of an inch or so of pubic hair-bearing skin, which keeps the scar nice and low and prevents the pubic hairline from rising halfway to the umbilicus, as is sometimes seen after standard abdominoplasties.
At any rate, the lines coming from above downward and below upward don't necessarily meet in one continuous grid. This is especially true in patients having a large panniculus (apron) of redundant skin. Some people who have seen my grid think that the vertical lines are used simply to line up the closure and that is not the case at all. With the markings made as I have described, the patient's hips are flexed at the beginning of the case and I use forceps to determine the most proximal point on line "M" that I can approximate to the bottommost line, the one 5 cm above the labial commissure. If that point lies, say, 2.5 cm below the umbilicus I know I can resect everything on a horizontal line extending outward from that point and along the lower curve I have drawn preoperatively. If that point falls at the umbilicus, the shape of the resection is the same but the proximal point is higher.
In the example, above, if I can easily approximate point "Y" (which is 2.5 cm below the umbilicus) to point "Z" with the patient's hips flexed at the beginning of the case, then the amount of tissue I resect includes everything between the horizontal black line containing the "Y" and the curved line containing the "Z." If I can approximate point "X" (which is at the umbilicus) to point "Z" then I will resected everything between the horizontal blue line containing the "X" and the curved line containing the "Z." This is a revolutionary way of determining the amount of tissue resection in an abdominoplasty.